Total hip replacement (THR), also known as total hip arthroplasty, is a highly effective surgical procedure that addresses severe deterioration of the hip joint. The process involves removing the damaged bone and cartilage and replacing them with engineered prosthetic components. This operation is widely considered one of the most successful in all of medicine, offering significant relief from pain and a substantial restoration of mobility. The primary goal of THR is to improve a patient’s quality of life by making everyday activities, such as walking and standing, easier to perform.
Conditions Leading to Hip Replacement
The most frequent cause of chronic hip pain leading to THR is degenerative joint disease, especially osteoarthritis. This condition, often called “wear-and-tear” arthritis, causes the protective cartilage covering the ends of the hip bones to wear away over time. When this cartilage is gone, the bones rub directly against each other, leading to stiffness and pain.
Other inflammatory and destructive conditions also necessitate a hip replacement. Rheumatoid arthritis is an autoimmune disease where the immune system attacks the joint lining, causing inflammation that can erode both cartilage and bone. Post-traumatic arthritis may develop following a severe hip injury, such as a fracture or dislocation. Avascular necrosis, or osteonecrosis, occurs when the blood supply to the femoral head is restricted, causing the bone tissue to die and collapse. Typically, surgery is considered only after non-surgical treatments like medication, physical therapy, and assistive devices fail to adequately manage the patient’s pain and functional limitations.
The Mechanics of Hip Replacement Surgery
A total hip replacement procedure generally takes between one and two hours, during which the surgeon systematically replaces the joint’s ball-and-socket mechanism. The process begins with an incision over the hip, followed by the surgical approach to access the joint; common approaches include the direct anterior, posterior, or lateral method. The choice of approach affects which muscles and tendons are moved or cut, influencing recovery speed and initial movement restrictions.
Once the joint is exposed, the first step is to dislocate the hip and remove the damaged femoral head, the “ball” of the joint. The surgeon then prepares the acetabulum, the hip socket, by removing the damaged cartilage and reaming the bone to a precise size. A metal shell, the acetabular cup, is then implanted into the pelvis to serve as the new socket.
Next, the hollow center of the femur, the thigh bone, is prepared to receive a metal stem. This femoral stem is either “press-fit” into the bone, encouraging bone growth, or secured with bone cement. A new prosthetic ball, typically made of metal or ceramic, is then placed onto the top of the stem, replacing the removed femoral head. The new joint surfaces—the ball and the cup’s liner (often specialized plastic, ceramic, or metal)—are then brought together to restore the smooth ball-and-socket articulation.
Preparing for and Managing Rehabilitation
Successful recovery from THR begins well before the operation with pre-operative planning, often called “prehab.” This stage includes a comprehensive medical evaluation to ensure the patient is healthy enough for surgery and to address any existing conditions. Patients are often advised to make necessary home modifications, such as arranging for a raised toilet seat, installing bathroom safety bars, and ensuring clear pathways for walking aids.
The post-operative recovery phase starts immediately, with mobilization beginning on the day of surgery or the following day. Physical therapists work with the patient to practice getting out of bed, walking short distances with a walker or crutches, and performing initial strengthening exercises. The goal of the typical one to two-day hospital stay is to manage pain effectively and ensure the patient can safely manage basic tasks before being discharged.
The early recovery period, lasting the first six weeks, focuses on adhering to specific hip precautions determined by the surgical approach, which are designed to prevent dislocation. Long-term rehabilitation involves a dedicated physical therapy program that focuses on strengthening the muscles surrounding the hip and improving flexibility. Full recovery and maximum functional improvement can take anywhere from three months to a full year.
Life with a New Hip Joint
One of the most reassuring aspects of THR is the long-term improvement in both pain and function. The procedure dramatically reduces the chronic, debilitating joint pain that led to the operation, allowing patients to return to most normal activities. Modern hip implants are designed for durability, with most expected to function well for 15 to 20 years, and many lasting even longer.
The longevity of the implant is highly dependent on patient activity level and body weight. Surgeons generally encourage low-impact activities that strengthen the surrounding muscles without placing undue stress on the joint:
- Walking
- Swimming
- Cycling
- Golfing
High-impact activities such as running, jumping, and aggressive contact sports are typically discouraged, as they accelerate the wear of the prosthetic components and can lead to the need for revision surgery. Maintaining a healthy weight and attending regular follow-up appointments help ensure the new hip joint remains functional.